The former commandant at Boradur Prison, Sefra is charged with maintaining the place after it is closed. Sefra takes advantage of his position to obtain Cesium-138--a vital component in nuclear weapons--and plans to sell it to the highest bidder. The chemical explodes when it reaches a temperature of 70 degrees, and Sefra keeps it under constant refrigeration. Sefra has also memorized the formula and destroyed it.
Sefra is a sadist and enjoyed torturing his prisoners regardless of their crimes. The IMF takes advantage of Sefra's sadism by sending Barney in. Barney is eventually "revealed" as an escaped prisoner. Sefra takes great delight in beating him to find out why Barney returned.
While Sefra is distracted, Dan sabotages the generator and the cesium's temperature rises when the refrigeration unit's power is lost. Panicking, Sefra takes the cesium to a local hospital's freezer room, unaware that Rollin is hiding inside. He puts the cesium in a mechanized wheeled drone, and then takes the drone to the tunnel leading into the prison. Barney "confesses" that Rollin is in the tunnel, Sefra goes in to get the cesium, and they send the drone toward him. It detonates, destroying the cesium and the only man who knows the formula.